There are image forming devices such as copying machines that read images on both sides of a document sheet while conveying it and generate image data, and then carry out image forming on both sides of a recording sheet based on the image data.
The image reading section (scanner) in an image forming device of this type has a reading device such as a solid image pick-up device of a plurality of pixels along the main scanning direction, and the document is read in two dimensions along the main scanning direction and the sub scanning direction by moving the document along the sub scanning direction with respect to the reading device. Such a type that reads a document while transporting it in this manner is called “a static exposure flow type” or “a sheet through type”, and this type will be referred to “a sheet through type” in this specification.
In an image forming device provided with an image reading section of this “sheet through type”, since it is possible to read a document while an optical mirror and an illuminating lamp are fixed, this type is suitable for reading several document sheets in succession.
Further, in an image forming device of this type, it is possible to read images on both sides of a document by reversing the document, and also, to reverse a recording sheet and form images on both sides of the recording sheet.
[Patent Document 1]
Japanese Patent Application Laid Open No. 2002-223336 (Page 1, FIG. 1)
[Patent Document 2]
Japanese Patent Application Laid Open No. 2002-359720 (Page 1, FIG. 1)
By the art disclosed in Patent Document 1 mentioned above, it is possible to designate single-sided output or double-sided output, according to read image data for each page, and image forming output is carried out both on a single side and double sides in a mixture, according to designated information. However, nothing has been mentioned about an image reading section, and reading of documents in a mixture of single-sided documents and double-sided documents has not been considered.
For example, it is necessary to insert a blank sheet in documents if it is necessary to insert a blank sheet in an output of image forming. Further, in a double-sided image forming mode, there is a problem of a drop in productivity because even a blank insertion sheet on which no image is formed is necessary to be passed through a double-sided image forming path.
Further, in the art disclosed in Patent Document 2, when the inter-sheet mode of inserting index sheets is designated, and if normal documents and tab sheet documents are present in a mixture, count values during reading are stored, and sheet feeding for image forming is switched, according to the count values. By storing count values in such a manner, it is understood that there is an assumption that a user loads normal documents and tab sheet documents on a document mounting portion in a plural times to read the documents.
Further, in an actual image forming device even if double-sided reading and double-sided image forming are possible with normal documents and recording sheets, the operations will be single-sided reading and single-sided image forming in the case of tab sheets due to the projecting part of the tabs.
In a known image forming device described above, when carrying out double sided copying of documents including tab sheet documents in the inter-sheet mode, if there are N sheets of tab sheet documents, since tab sheet documents are not in a series, the user has to divide the documents into 2N+1 bundles and mount the bundles at the document mounting position alternately in plural times to have them read.
In other words, in this case, operation and control are necessary not as a single continuous job but as a programming job to be handled as 2N+1 multiple jobs. In such a programming job method, as the reading is not for a single integrated bundle, there is a problem that the productivity is sacrificed and the efficiency is low.
Further, there is also a problem that the task is tedious because the user has to load documents in several times.
Further, consideration is not given to carrying out a mixture of double-sided and single-sided image forming in a state where both single-side and double-side documents are present. In other words, also in this case, operation and control were necessary not as a single continuous job but as a programming job to be handled as several jobs. In this programming job method, there is a problem that the productivity is sacrificed and the efficiency is low because reading of documents is not for a single integrated bundle.
The case of a copying machine has been described above. In the case of image forming devices such as printers, etc., that receive image data from outside and carry out image forming, although it is possible to designate various types of settings regarding printing in an application program generating image data, consideration has not been given to operationability for designating a single-sided mode or double-sided mode for insertion sheets.